export const downXml = (json, fileName = 'xxxx.xlsx') => {
  try {
    const sheet = window.XLSX.utils.json_to_sheet(json);
    openDownloadDialog(sheet2blob(sheet, undefined), fileName);
  } catch (e) {}
};

function openDownloadDialog(url, saveName) {
  let linkUrl = url;
  if (typeof url == 'object' && url instanceof Blob) {
    linkUrl = URL.createObjectURL(url); // 创建blob地址
  }
  var aLink = document.createElement('a');
  aLink.href = linkUrl;
  aLink.download = saveName || ''; // HTML5新增的属性，指定保存文件名，可以不要后缀，注意，file:///模式下不会生效
  var event;
  if (window.MouseEvent) event = new MouseEvent('click');
  else {
    event = document.createEvent('MouseEvents');
    event.initMouseEvent(
      'click',
      true,
      false,
      window,
      0,
      0,
      0,
      0,
      0,
      false,
      false,
      false,
      false,
      0,
      null,
    );
  }
  aLink.dispatchEvent(event);
}
function sheet2blob(sheet, sheetName = 'sheet1') {
  var workbook = {
    SheetNames: [sheetName],
    Sheets: {},
  };
  workbook.Sheets[sheetName] = sheet; // 生成excel的配置项

  var wopts = {
    bookType: 'xls', // 要生成的文件类型
    bookSST: false, // 是否生成Shared String Table，官方解释是，如果开启生成速度会下降，但在低版本IOS设备上有更好的兼容性
    type: 'binary',
  };
  var wbout = XLSX.write(workbook, wopts);
  var blob = new Blob([s2ab(wbout)], {
    type: 'application/octet-stream',
  }); // 字符串转ArrayBuffer
  function s2ab(s) {
    var buf = new ArrayBuffer(s.length);
    var view = new Uint8Array(buf);
    for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xff;
    return buf;
  }
  return blob;
}
